The present invention relates to polyetheramide acid and polyetherimide compositions having terminal aliphatically unsaturated end groups. Prior to the present invention, as shown by Heath et al U.S. Pat. No. 3,847,867, assigned to the same assignee as the present invention, polyetherimides were provided by effecting reaction between certain aromatic bis(etheranhydride) and organic diamine. The polyetherimides could be reinforced with fillers to produce high performance composites. The polyetherimides of Heath et al have valuable flow characteristics as distinguished from conventional polyimides which are intractable upon conversion to the polyimide state. However, in particular applications requiring toughness and the ability to form a thermoset as distinguished from a thermoplastic, the polyetherimides of Heath et al do not possess the required chemical functionality which are often needed in making high strength composites or tough flexible films.
Attempts to achieve a suitable balance in processability and good mechanical properties in polyimides are shown by Lubowitz U.S. Pat. Nos. 3,528,950 and 3,781,241, based on the use of organic dianhydrides, such as benzophenone tetracarboxylic acid dianhydride and organic diamine, such as methylene dianiline in combination with specific endcapping monoanhydrides. An additional effort is shown by Winter U.S. Pat. No. 3,842,143 based on the use of amine terminated polyimides in combination with reactive polyolefinic compounds. According to Winter, the polyolefinic compounds were separately synthesized and when added to the amine terminated polyimide, there was effected a lowering of the softening temperature. The various procedures provided by the prior art to make processable thermosetting polyimides were often based on complicated synthetic techniques and the resulting thermosets were often deficient in ease of processability.